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On Thu, 31 Jan 2008 23:14:05 +0000, Kay Robinson
wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.

The two sites are 45km apart (about 28 miles) so this is not possible.
I guess you are somewhere near Uppermill then which is a bit further than
5 miles from HM.

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On Fri, 01 Feb 2008 05:37:56 -0600, "m.t6" wrote:

Kay Robinson wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.


The higher you are the weaker the signal will be due to the way
the antenna system works at the transmitter. The power is sent into
the high population areas, which are usually in the valleys.

I live about 500' above sea level, 4 miles from the nearest shop. The
biggest towns nearby, served by the same transmitter (Black Hill) are,
I'd estimate, mostly at less than 60' (Stirling and Falkirk). I get
artifact-free DTT on a cheap set-top aerial.
--
http://www.robinfaichney.org/

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In article ,
Robin Faichney wrote:
On Fri, 01 Feb 2008 05:37:56 -0600, "m.t6" wrote:

Kay Robinson wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.


The higher you are the weaker the signal will be due to the way
the antenna system works at the transmitter. The power is sent into
the high population areas, which are usually in the valleys.

I live about 500' above sea level, 4 miles from the nearest shop. The
biggest towns nearby, served by the same transmitter (Black Hill) are,
I'd estimate, mostly at less than 60' (Stirling and Falkirk). I get
artifact-free DTT on a cheap set-top aerial.

There is (almost) always 'beam tilt' on tv transmitters, usually only a few
degrees. But remember that there is earth curvature, so if you are far
enough away you could still be in the main part of the beam. However, if
you are reasonably close and higher than the transmit aerials, you will be
above the beam - most often this is noticeable on small relay sites which
aren't on the top of the local hill.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

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In message , charles
writes
In article ,
Robin Faichney wrote:
On Fri, 01 Feb 2008 05:37:56 -0600, "m.t6" wrote:

Kay Robinson wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.


The higher you are the weaker the signal will be due to the way
the antenna system works at the transmitter. The power is sent into
the high population areas, which are usually in the valleys.

I live about 500' above sea level, 4 miles from the nearest shop. The
biggest towns nearby, served by the same transmitter (Black Hill) are,
I'd estimate, mostly at less than 60' (Stirling and Falkirk). I get
artifact-free DTT on a cheap set-top aerial.

There is (almost) always 'beam tilt' on tv transmitters, usually only a few
degrees. But remember that there is earth curvature, so if you are far
enough away you could still be in the main part of the beam. However, if
you are reasonably close and higher than the transmit aerials, you will be
above the beam - most often this is noticeable on small relay sites which
aren't on the top of the local hill.


If I am (say) 20 miles from a main transmitter, and there is no limit on
the height to which I can raise my TV aerial, how high would it have to
be before the signal strength began to fall (assuming lossless coax)?
And, if the coax was (say) CT100, again, how high?
--
Ian

BBC/ITV Freesat, another tiny drop of info...
 

In article ,
Ian Jackson wrote:

If I am (say) 20 miles from a main transmitter, and there is no limit on
the height to which I can raise my TV aerial, how high would it have to
be before the signal strength began to fall (assuming lossless coax)?
And, if the coax was (say) CT100, again, how high?


It would depend on the height of the mast. You do the trigonometry. Assume
a beam tilt of 6 degrees.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

BBC/ITV Freesat, another tiny drop of info...
 

wrote:

If I am (say) 20 miles from a main transmitter, and there is no limit on
the height to which I can raise my TV aerial, how high would it have to
be before the signal strength began to fall (assuming lossless coax)?
And, if the coax was (say) CT100, again, how high?


It would depend on the height of the mast. You do the trigonometry. Assume
a beam tilt of 6 degrees.

3 degrees would be an exceptionally large beam tilt for a main station. 1-2
deg would be the norm.


It depends upon required coverage area.

Also a station such as Winter Hill may have its power reduced in certain
directions.

BBC/ITV Freesat, another tiny drop of info...
 

In my local Comet most of the tvs have their own advert showing, the
rest (abt 25%) have the usual mix on morning/afternoon programmes put
out on Freeview. It sounds to me as if the signal maybe isn't up to
scratch were you view them.

It is..

My local Asda has a large number on
display, most off and maybe a dozen on (all Freeview) and will switch
any on and connect the aerial on request. Have you asked at your local
Comet/Currys for a demo using Freeview?

No I haven't .. but most everything I've seen of freeview inc here, we
do have a couple of freeview boxes, isn't what it should be..

If they won't do it take a
trip over here. Comet even have several special viewing 'rooms' to
which they'll roll in the telly you want to see and connect it up so
you can sit on the sofa and watch from whatever other equipment you
may want added or none as the case might be.

Bl**dy don't have that in Cambridge!...

Kay

(\__/)
(='.'=) This is Bunny. Copy and paste Bunny into your
(")_(") signature to help him gain world domination.

--
Tony Sayer

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In article , m.t6 [email protected]?.? scribeth thus
Kay Robinson wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.


The higher you are the weaker the signal will be due to the way
the antenna system works at the transmitter. The power is sent into
the high population areas, which are usually in the valleys.

Also Holme Moss doesn't transmit television.



Not really. The down tilt angle at more than a couple of miles from a TX
won't really have any effect...

and I doubt that there are many if any viewers above the top of the
winter hill mast;)

I'm happy to be proved wrong about that;)..


--
Tony Sayer

BBC/ITV Freesat, another tiny drop of info...
 

tony sayer wrote:

Maybe it's just that I get a stronger signal than you have. I'm 5
miles off Holme Moss and 20 miles off Winter Hill, and high up.


The higher you are the weaker the signal will be due to the way
the antenna system works at the transmitter. The power is sent into
the high population areas, which are usually in the valleys.

Also Holme Moss doesn't transmit television.



Not really. The down tilt angle at more than a couple of miles from a TX
won't really have any effect...

and I doubt that there are many if any viewers above the top of the
winter hill mast;)

I'm happy to be proved wrong about that;)..


It has a effect on the radio horizon.

BBC/ITV Freesat, another tiny drop of info...
 

In article ,
wrote:
On 1 Feb,
charles wrote:

In article ,
Ian Jackson wrote:

If I am (say) 20 miles from a main transmitter, and there is no limit
on the height to which I can raise my TV aerial, how high would it
have to be before the signal strength began to fall (assuming
lossless coax)? And, if the coax was (say) CT100, again, how high?


It would depend on the height of the mast. You do the trigonometry.
Assume a beam tilt of 6 degrees.

3 degrees would be an exceptionally large beam tilt for a main station.
1-2 deg would be the norm.

I was probably thinking of relays.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11